Delete the ChipLock mutex as well in the shutdown.

Author: jadhavrohit924

src/include/platform/internal/GenericPlatformManagerImpl_FreeRTOS.ipp

@@ -422,6 +422,7 @@ void GenericPlatformManagerImpl_FreeRTOS<ImplClass>::_Shutdown(void)
         mBackgroundEventQueue = NULL;
     }
 #endif
+    vSemaphoreDelete(mChipStackLock) mChipStackLock = NULL;
     GenericPlatformManagerImpl<ImplClass>::_Shutdown();
 }